What is P&ID?
It stands for Piping and Instrumentation diagram.
It gives the over all idea about the process.
Why to use P&ID?
To describe over all plant and instrumentation.
It shows the flows in a plant and the corresponding sensors or other equipment.
It gives name to each sensors and other equipment along with their parameter.
The P&ID mixes pneumatic / hydraulic elements,electrical elements and instrumentation on the same diagram.
It uses a set of symbols defined in the ISA S5.1 standard
Examples of hydraulic / pneumatic symbols
P&ID Should be included with
All process equipment (With its tag number)
All pipes (With line number)
All valves with identification no along with their type and size should be shown.
Pumps with tag number
All control loops and instruments with identification.
Common Connection Lines
How to read P&ID ?
Discrete instruments are indicated by circular elements
Shared control/display elements are circles surrounded by a square.
Computer functions are indicated by a hexagon
Programmable logic function are shown as a triangle inside a square.